Congress president Sonia Gandhi on Monday shot down Lok Sabha member Shashi Tharoor’s request to allow him to attend a CPM seminar, choosing to support the Kerala unit’s stand against the idea.

Although Tharoor said he was not going to praise the CPM, Sonia delivered a stern message: Listen to the Kerala leadership.

Tharoor and Congress veteran K.V. Thomas, a former Union minister from Kerala, later said they would honour Sonia’s decision and not attend the seminars at the upcoming CPM national congress to which they had been invited.

Both leaders had earlier dismissed a warning from Kerala Congress president K. Sudhakaran not to attend the seminars, arguing the event was not a state-level one and citing the Congress-CPM cooperation at the Centre.

Sonia issued her diktat at a meeting with Kerala MPs where the dominant opinion was that Tharoor’s participation at the CPM event would send out a wrong message at a time the Congress was locked in a fierce battle with the Pinarayi Vijayan government.

Tharoor, Thomas and Mani Shankar Aiyar from the Congress had been invited to speak at seminars to be held as part of the CPM national congress in Kannur from April 6 to 10.

While Thomas is seen as a disgruntled politician and Aiyar had once been suspended from the party, Tharoor is the sitting MP from Thiruvananthapuram and a prominent Congress face. He is also chief of the All India Professional Congress.

After Sudhakaran said on Sunday that all Congress leaders should stay away from CPM seminars or face disciplinary action, Tharoor had on Monday morning expressed willingness to attend the April 9 event he had been invited to.

“The invitation is for a national event and I must say that the concerns expressed will have to be taken seriously and I will await the guidance of the party high command,” he had told reporters outside the Parliament building.

“There is nothing related to Kerala in the invitation. I have been asked to address a question of Centre-state relations in a seminar alongside the Kerala chief minister and the Tamil Nadu chief minister. None of the controversial issues of Kerala are going to be addressed in this seminar.”

Sudhakaran had said that at a time when the CPM was inflicting agony on the people in the name of the semi-high-speed railway project K-Rail Silverline, the public would develop contempt towards Congress leaders if they participated in such seminars.

Tharoor believes in having a continuing political dialogue between adversaries. While he has consistently criticised the BJP’s policies, particularly the rise of communal hatred on Narendra Modi’s watch, he has often argued that political opposition cannot lead to a termination of social courtesies or appreciation of good work.

Recently on his birthday, he said he was touched and delighted to receive greetings from Prime Minister Modi and Union home minister Amit Shah.

Tharoor had responded warmly to everybody who greeted him but there were misgivings in the party about his enthusiastic response to the overtures from Modi and Shah.

While Sonia has endorsed the ban on attending the CPM event, she had herself hosted all the Opposition parties, including the Left, on multiple occasions to draw up strategies against the BJP.

Rahul Gandhi too has an excellent rapport with CPM general secretary Sitaram Yechury, whose election to the Rajya Sabha from Bengal the Congress had supported. The Congress had fought the Bengal Assembly elections in alliance with the Left when its Kerala unit was fighting ferociously to dislodge the CPM government.

Late on Monday, Tharoor issued a statement saying: “I respect her (Sonia’s) views on this matter and have conveyed to the organisers my inability to participate.”

He said he had been invited to a seminar at the CPM’s Kerala state committee meeting recently. “On that occasion also I had consulted the AICC president and a suitable decision was taken without any media controversy,” he said.

Thomas told The Telegraph: “I will honour the party president’s decision and will not be participating in the seminar.”

Thomas is believed to be unhappy at being denied a Rajya Sabha ticket. He had been invited to an April 7 seminar on the challenges faced by secularism.